Many different types of polyolefin containers having interior compartments are formed by injection molding plastic between a female and male mold. The male mold typically includes a plurality of upstanding spaced apart cores fixedly mounted at their bottom ends to a base. The cores are spaced apart to form the partitions separating the various compartments within the container. Due to the large injection pressure, in the neighborhood of 20,000 psi, the free distal ends of the cores move thereby causing the compartment partitions to be irregular in thickness. This problem was solved by the invention disclosed in U.S. Pat. No. 3,473,197 wherein the free distal ends of the cores are rigidly secured together by wedges mounted to the female mold and extending between the cores of the male mold. A different approach is disclosed in U.S. Pat. No. 4,278,417 wherein transverse locking pins are provided on each core to engage the adjacent core.
The size of the compartment molded in a container is determined by the size of the respective core on the male mold. Thus, small compartments require relatively thin cores decreasing the rigidity of the core and allowing for freer movement of the free distal core end. Further, it becomes more difficult to incorporate the transverse pin locking mechanism disclosed in U.S. Pat. No. 4,278,417 in a thin core. It is therefore desirable to provide a new and effective means for controllling the transverse movement of the free distal core end in molds having relatively thin cores. Disclosed herein is such a device and method.